Zinc supplementation in infants with a nutritional pattern of failure to thrive: a double-blind, controlled study.

The objective of this study was to determine whether zinc deficiency is one of the factors involved in nutritional failure to thrive in infants and toddlers. Participants were selected on the basis of anthropometric criteria, particularly a decline in weight velocity preceding changes in length gains. The investigation was designed as a double-blind, randomized, pair-matched, controlled study of dietary zinc supplementation of 6 months' duration. Anthropometric data were collected at 0, 1, 3, and 6 months. Twenty-five pairs of infants completed the project. When compared with placebo-treated control children, the zinc-supplemented group (combined sexes) and the supplemented boys showed significant improvements in standard deviation scores for weight for all three intervals, the largest differences occurring for the 0- to 3-month interval (P less than or equal to .0001). The zinc-supplemented girls demonstrated a trend toward improvements in changes in standard deviation scores for weight (P = .056). There were no differences in length gains for either boys or girls. This improvement in weight gains after zinc supplementation demonstrates that mild zinc deficiency can be one of the etiologic factors in nutritional failure to thrive during infancy.